Ask anyone to make a list of
the worst natural disasters, and you’re likely to get a dissertation on
the relative risks of hurricanes, floods, tornadoes, and similar
terrestrial events. A solar storm, in contrast, is unlikely to make
anyone’s Top 5. According to Joseph N. Pelton, the former dean of the
International Space University, that’s a critical error in thinking that
we need to address.

Pelton, who also serves as a board member of the International Association of Space Safety (IAASS), argues that humanity should create an artificial Van Allen belt
to supplement the natural Van Allen belts that already exist around
Earth. These belts extend from an altitude of 600 to 36,000 miles above
the Earth’s surface and form a natural shield that prevents high-energy
particles from hitting the Earth’s atmosphere.

Ordinarily, the Earth’s magnetosphere shapes
the Van Allen Belts and deflects the charged particles emitted by the
sun (called the solar wind), while the VABs act to block high-energy
electrons. Periodically, however, the sun releases solar flares. These
flares are high-energy events that release a concentrated burst of
energy in a particular direction. If that direction happens to be
towards us, it can temporarily compress the magnetic field and allow
high-energy particles through the Van Allen Belts. The largest flares
are sometimes accompanied by a coronal mass ejection — and as Pelton
notes, these have the potential to wreak serious damage on both
satellites and Earth infrastructure.

Earth’s magnetosphere. Artist’s rendition.

There’s certainly reason for concern. On
September 1, 1859, the most powerful geomagnetic storm of modern times
hit the Earth. Aurorae, normally visible only at high latitudes, reached
the Caribbean. The glow over the Rocky Mountains was so bright, gold
miners reportedly exited their tents and began preparing breakfast.
Telegraphs failed across the world — though in some areas, they
continued to send and receive messages, even after being disconnected
from their electrical supplies.

The event became known as the Carrington
Event, after British astronomer Richard Carrington — but what caused
small problems and unusual events in the 1800s would be absolutely
devastating today. The handful of moderate geomagnetic storms in the
last 40 years have caused significant damage to the grid; a full
hammerblow would destroy the US electrical grid for several years. The
economic impact of a similar disaster today is estimated at $2.6
trillion.

Often, when online publications write
disaster-themed science stories, there are a number of comforting facts
buried below the lede to take the edge off. Sure, a dinosaur-level extinction event
could make for a really rocky millennium or two on Earth, but the
chances of a rock that big hitting the planet are minuscule. Reading up
on the potential impact [PDF] a coronal mass ejection (CME) could have on Earth offers no such comfort.

The truth is, solar flares as large as the one
that caused the 1859 Carrington Event happen fairly regularly. Since we
started monitoring the Sun’s solar cycle, we’ve gotten lucky on a
number of occasions — CMEs that would have hit us even harder than 1859
have merely glanced us due to a non-ideal trajectory. Meanwhile, the
United States’ grid is more vulnerable to such events than ever before —
our transformer grid is, on average, nearly 40 years old, high-voltage
power lines are carrying far more energy than they used to on a
day-to-day basis, and there’s virtually no way to quickly repair the
damage such a storm would cause.

Cloudy with a chance of civilization-crippling electromagnetic forces

Just how much of a threat is this? We
consulted the Department of Energy’s own research to get a better idea.
According to that report, transformers are custom-designed, highly
intricate, take up to two years to manufacture, cost between $5-7
million apiece, and weigh between 100 and 400 tons. Ordinary
transformers are far too bulky and heavy to ship by road, and must be
moved around the country in specially-designed railcars. Smaller models
are available, but are typically more expensive.

The United States power grid is utterly
incapable of weathering a devastating geomagnetic storm. In worst-case
scenarios, the sheer amount of energy flowing down the high-voltage wire
would blow transformers in quick succession. The automatic load
balancing and considerable safety margins that are built into plants are
designed to deal with terrestrial disasters, not space invasions.
Offline power capacity normally used for supplementing baseline power
during peak hours might survive, but these plants are not staffed or
fueled for long duration. Up to 92% of the Northeast’s power generation
capability could be taken offline for periods of several years.

A cascade failure that took out such a huge
swath of our power generation would have untold downstream effects, as
people lost the ability to contact emergency services, lost water
pressure in areas that rely on electrical pumps, and were forced to rely
on limited generator power. The damage estimates aren’t just
theoretical — we know the electrical grid is sensitive to such
geomagnetic storms after a surge in 1989 caused a major failure of a
hydroelectric generator in Quebec. In the wake of that event, some of
the US-based power companies instituted safeguards, but they’re woefully
lacking compared to what could hit us.

Infrastructure protection

Even moderate geomagnetic storms cause
significant damage or accelerate failures in equipment. Two years after
the 1989 storm, 12 mid-sized transformers had failed — all of them
significantly earlier than had otherwise been expected. During solar
storms on April 3-5 1994, major transformers failed in Illinois at the
Zion Nuclear plant as well as facilities in Braidwood and at the
Powerton coal plant.

The windings in this transformer were oil-cooled and rated for 3,000 amps.

The good news is, there are ways to protect
the grid and mitigate the damage that another Carrington event would
cause. The bad news is, we’re mostly not doing them, despite the
catastrophic damage such an event will cause. The Washington DC/New York
City corridor is considered to be most at-risk, with 20-40 million
people in danger. It would cost several billion dollars to protect
existing lines, far less than the $2.6 trillion quoted above from an
actual impact.

Unlike dinosaur-level extinction events,
geomagnetic storms that cause enormous disruptions in the Earth’s
magnetic field are a regular phenomenon and were reported widely in
historical journals and writings, stretching back to the dawn of human
history. Storms with the power of the 1859 CME hit, on average, every
154 years.

With all that said, Pelton’s proposal to build
an artificial VAB and link it to beaming solar power is probably
unworkable with present technology. Space-based solar is an exciting
concept with limited applicability given the expense of launching solar
panels, the relatively quick degradation of said panels (panels in space
break down about 8x more quickly than the same panels on Earth), the
real risk of space debris destroying an orbiting array, and the cost of
the receiving station on the ground. Then there’s the intrinsic energy
loss of gathering energy in space, converting it to microwaves for
transmission, beaming it back to the ground, and then converting it back into electricity.

Regardless of the feasibility of his proposed
solution, Pelton isn’t wrong about the problem. The internet, like most
of the rest of the United States critical infrastructure, is not
defended properly against geomagnetic storms. A second Carrington event
could destroy critical hardware that would take us years to fix.